• KEPCO Journal on Electric Power and Energy
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• 제7권2호
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• pp.277-283
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• 2021

Power plant simulators have been used for operator training, control verification and engineering verification. In general, simulators can be used in the place where they are installed by only single user group at a time. Considering high cost of simulator development, a lot of available scenarios, the diversity of user level and accessibility based on users' work location, development of simulator system that can be used by multiple user groups regardless of location is required in order to enhance utilization of simulators. In this paper, the simulator system that can be used by multiple user group simultaneously without location limitation is proposed. The simulator system is composed of simulator servers, database servers, HMI servers, a web server, web clients. Simulator server consists of control model, process model that are developed for Circulating Fluidized Bed power plant located overseas. A web server manages user accounts, operation procedures, multiple server access between web client group and simulator server group. In other words, a web server makes a user group select a simulator server at a time. The developed simulator system is integrated after implementing process model, control model, HMI, and web server. Web client systems are installed on local site where power plant is located, while simulator servers, HMI servers, database servers, and a web server are located in KEPCO RI. The developed simulator system is verified by steady-state test, malfunction test and so on via remote access.

• 한국산업정보학회논문지
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• 제9권3호
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• pp.19-31
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• 2004

본 연구는 웹서버와 비주얼 인터데브를 각각 서버, 클라이언트의 개념적 툴로 사용해서 인터넷이나 인트라넷상에서 웹 애플리케이션을 개발하는 방법과 이 애플리케이션에 데이터베이스를 동적으로 통합하는 사례를 보임으로써 데이터베이스 정보를 다루는 파일과 웹 페이지를 다루는 파일을 각각 따로 개발하지 않고도 비주얼 인터데브를 이용하면 하나의 통합환경 안에서 쉽고도 강력한 동적 웹데이터베이스를 개발할 수 있다는 사례를 보이고 향후 보다 적은 코딩 작업으로 보다 더 쉽게 웹 프로그램을 개발할 수 있는 기법과 원리를 제공하고자 함에 그 목적이 있다.

• 전자공학회논문지 IE
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• 제43권4호
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• pp.60-64
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• 2006

이 시스템은 위치정보를 얻기 위한 무선통신기의 특성상 중계기의 설치간격에 따라 정보의 범위가 제한되는 것을 보완하기 위한 체계를 구축한다. 주차장 관리 시스템은 주차 정보의 데이터베이스를 구축하고 데이터베이스 정보는 클라이언트와 관리자에게 용이하게 제공할 수 있도록 설계되었다. 주차장에 설치된 무선 통신 장치에는 센서가 부착되어 차량을 감지할 수 있고, 이 데이터는 서버에게 주차위치 기본 정보를 전송한다 무선 핸드폰 에뮬레이터 J2MEWTK를 클라이언트로 하여 서버의 연동을 확인했고, 주차정보의 전송을 통한 서버 주차관리 데이터베이스의 정보 가공을 확인하였으며, 서버와 관리자를 위한 관리자 프로그램은 사용자 편의와 관리에 용이한 메뉴화면을 제공하였다.

• 정보처리학회논문지D
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• 제15D권1호
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• pp.147-154
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• 2008

인터넷이 대중화 되면서 내부 데이터베이스로 관리되고 있는 정보를 동적 웹 서버 페이지를 작성하여 웹으로 제공하는 다양한 웹 어플리케이션 개발이 수행되고 있으나, 대부분의 경우 체계적인 개발 방법론의 채택 없이 직접 프로그램을 작성하거나, 규모에 맞지 않는 대규모 개발 방법론을 적용하여 개발의 효율성을 떨어뜨리고 있다. 웹 어플리케이션이 체계적인 개발 방법론을 따르지 않고 스크립트 언어를 사용하여 임의개발 됨에 따라 프로그램 개발의 생산성, 유지 보수성, 그리고 재 사용성을 저하시키게 된다. 본 논문에서는 빠르고 효과적인 스크립트 기반의 웹 어플리케이션 개발을 위하여 데이터베이스를 이용한 동적 웹 서버 페이지 자동 작성 도구를 설계하고 이를 구현하였다. 데이터베이스를 이용한 동적 웹 서버 페이지 패턴을 분석하여 정형화된 스크립트 모델을 제시하고 데이터 바운드 컨트롤 태그 생성기를 표준 스크립트로 작성하여 웹 어플리케이션 개발과 유지보수에 활용되어 생산성 향상에 기여할 수 있다.

• 한국IT서비스학회지
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• 제14권4호
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• pp.257-267
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• 2015

We propose a vehicle-mounted, location-aware mobile digital signage system that can be used for public transportation through mobile communication. This paper proposes the installations of the LED display panels at the backside of the bus., which display traffic information to cars behind the bus. Information to be displayed would include, but is not limited to, road information, public commercials and private commercials. We propose the system architecture and further implement the prototype of mobile digital signage system for demonstration. The system is based on the Client-Server system. Each bus has a client terminal which detects the current location by a GPS receiver and sends its location information to the server using mobile communication function. The terminal device receives advertisements and traffic information from the server and displays it to the large LCD or LED panel installed at the inside and outside of the bus. We use the Android smartphone as a client system, which inherently equipped with GPS and mobile communication function. GPS detects the location of bus and reports its geo-location data to the traffic information center server via a wireless communication network. On the server side, we developed a specially designed control server, where it communicates with the other traffic information center and updates and manages the databases contents being displayed by each position. The server contains location dependent variable information and returns selected information back to the vehicle in real time. Spatial database is used to process location based data. Server system periodically receives the real time traffic information from the road information center database. And it process the information by bus location and bus line number. In this paper, we propose a mobile digital signage service and explain the system implementation of this service.

• 산업기술연구
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• 제29권B호
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• pp.157-163
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• 2009

In this paper, we implement a place information system for missing children using embedded board. In the implementation, the embedded board receives location information from GPS satellites, parsing GGA information which includes current time and location coordinates from the satellite information and sends them to the location management server. The server locates a missing child using the location information from embedded board together with server database. We implement an application program for the system. The program shows current location of a child and its moving path and browses the corresponding map from coordinates mapping.

• 경영정보학연구
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• 제3권2호
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• pp.277-288
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• 2001

Of critical importance to the success of any e-commerce site are the two factors: rapid application development and quick response time. A three-tier architecture composed of presentation layer, business layer, and data access layer emerges to allow rapid changes in user interface, business logic, and database structures. Too often, such a logical three-tier architecture is considered as requiring a three-tier physical architecture: Web server, application server, and database server running on separate computers. Contrary to the common belief, a Web stress test reveals that the three-tier logical architecture implemented on a two-tier physical platform guarantees a quicker response time due to the reduction in cross-machine communications. This would lead business firms to economize their spending on e-commerce: increasing the number of physical servers to expedite transaction is not necessarily the best solution. Before selecting a particular hardware configuration, a Web stress test needs to be conducted to compare the relative merits of alternative physical architectures. Together with capacity planning, Web stress test emerges as a powerful tool to build robust, yet economical e-commerce sites.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.457-460
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• 2002

This paper is study on internet based remote control and monitoring for the system to purify water. environment of the water quality grew worse. therefore we require the effective system to purify water now national internet based remote control and monitoring make a sensation and are a problem to be solved. This paper demonstrate internet based remote control and monitoring for the system to purify water. This system including on server and many client distributed in whole country. The server is collecting information from the client. this information is then written inside Database. The Database is dealing with Website and Server and Client.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권10호
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• pp.4198-4213
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• 2020

Data encryption, particularly application-level data encryption, is a common solution to protect data confidentiality and deal with security threats. Application-level encryption is a process in which data is encrypted before being sent to the database. However, cryptography transforms data and makes the query difficult to execute. Various studies have been carried out to find ways in order to implement a searchable encrypted database. In the current paper, we provide a new encrypting method and querying on encrypted data (ZSDB) for different data types. It is worth mentioning that the proposed method is based on secret sharing. ZSDB provides data confidentiality by dividing sensitive data into two parts and using the additional server as Dictionary Server. In addition, it supports required operations on various types of data, especially LIKE operator functioning on string data type. ZSDB dedicates the largest volume of execution tasks on queries to the server. Therefore, the data owner only needs to encrypt and decrypt data.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2115-2117
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• 2003

This paper is study on internet based wireless remote control and monitoring for the system to purify water. Environment of the water quality grew worse. Therefore we require the effective system to purify water. Now national internet based wireless remote control and monitoring make a sensation and are a problem to be solved. This paper demonstrate internet based wireless remote control and monitoring for the system to purify water. This system including on server and many client distributed in whole country. The server is collecting information from the client. This information is then written inside database. The database is dealing with website and server and client.